Randomly getting the "Integrity constraint violation" sql error on saving entry from backend. There no apparent cause of this at least not that I can see, because the same post saves without errors when I try again.
Craft version is : 2.6.3017
Here is the error and Stack trace:
[error] [system.db.CDbCommand] CDbCommand::execute() failed: SQLSTATE[23000]: Integrity constraint violation: 1452 Cannot add or update a child row: a foreign key constraint fails (`db_production`.`craft_relations`, CONSTRAINT `craft_relations_targetId_fk` FOREIGN KEY (`targetId`) REFERENCES `craft_elements` (`id`) ON DELETE CASCADE). The SQL statement executed was: INSERT INTO `craft_relations` (`fieldId`, `sourceId`, `sourceLocale`, `targetId`, `sortOrder`, `dateCreated`, `dateUpdated`, `uid`) VALUES (:row0_col0, :row0_col1, NULL, :row0_col3, :row0_col4, :row0_col5, :row0_col6, :row0_col7), (:row1_col0, :row1_col1, NULL, :row1_col3, :row1_col4, :row1_col5, :row1_col6, :row1_col7), (:row2_col0, :row2_col1, NULL, :row2_col3, :row2_col4, :row2_col5, :row2_col6, :row2_col7), (:row3_col0, :row3_col1, NULL, :row3_col3, :row3_col4, :row3_col5, :row3_col6, :row3_col7), (:row4_col0, :row4_col1, NULL, :row4_col3, :row4_col4, :row4_col5, :row4_col6, :row4_col7), (:row5_col0, :row5_col1, NULL, :row5_col3, :row5_col4, :row5_col5, :row5_col6, :row5_col7).
[error] [exception.CDbException] CDbException: CDbCommand failed to execute the SQL statement: SQLSTATE[23000]: Integrity constraint violation: 1452 Cannot add or update a child row: a foreign key constraint fails (`db_production`.`craft_relations`, CONSTRAINT `craft_relations_targetId_fk` FOREIGN KEY (`targetId`) REFERENCES `craft_elements` (`id`) ON DELETE CASCADE) in /var/www/mysite.com/craft/app/framework/db/CDbCommand.php:358
Stack trace:
#0 /var/www/mysite.com/craft/app/etc/db/DbCommand.php(370): CDbCommand->execute(Array)
#1 /var/www/mysite.com/craft/app/services/RelationsService.php(74): Craft\DbCommand->insertAll('craft_relations', Array, Array)
#2 /var/www/mysite.com/craft/app/fieldtypes/BaseElementFieldType.php(291): Craft\RelationsService->saveRelations(Object(Craft\FieldModel), Object(Craft\EntryModel), Array)
#3 /var/www/mysite.com/craft/app/services/ElementsService.php(1608): Craft\BaseElementFieldType->onAfterElementSave()
#4 /var/www/mysite.com/craft/app/services/EntriesService.php(176): Craft\ElementsService->saveElement(Object(Craft\EntryModel))
#5 /var/www/mysite.com/craft/app/controllers/EntriesController.php(462): Craft\EntriesService->saveEntry(Object(Craft\EntryModel))
#6 /var/www/mysite.com/craft/app/framework/web/actions/CInlineAction.php(49): Craft\EntriesController->actionSaveEntry()
#7 /var/www/mysite.com/craft/app/framework/web/CController.php(308): CInlineAction->runWithParams(Array)
#8 /var/www/mysite.com/craft/app/framework/web/CController.php(286): CController->runAction(Object(CInlineAction))
#9 /var/www/mysite.com/craft/app/framework/web/CController.php(265): CController->runActionWithFilters(Object(CInlineAction), Array)
#10 /var/www/mysite.com/craft/app/framework/web/CWebApplication.php(282): CController->run('saveEntry')
#11 /var/www/mysite.com/craft/app/etc/web/WebApp.php(836): CWebApplication->runController('entries/saveEnt...')
#12 /var/www/mysite.com/craft/app/etc/web/WebApp.php(287): Craft\WebApp->_processActionRequest()
#13 /var/www/mysite.com/craft/app/framework/base/CApplication.php(185): Craft\WebApp->processRequest()
#14 /var/www/mysite.com/craft/app/index.php(73): CApplication->run()
#15 /var/www/mysite.com/public/index.php(15): require_once('/var/www/mysite...')
#16 {main}
REQUEST_URI=/admin/entries/blog/new
HTTP_REFERER=https://mysite.com/admin/entries/blog/new
Anyone ever faced this error? is this a Craft bug?